1. Field of the Invention
The present invention relates to an air conditioning system for vehicles capable of controlling the air-distribution in accordance with the direction of the sun.
2. Description of the Prior Art
There have been proposed various air conditioning systems for vehicles of the type in which the ratio between the amounts of air discharged to the left and right sides of the passenger compartment (hereinafter referred to as the air-distribution ratio) is changed depending upon the amount of solar radiation striking the left and right sides of the passenger compartment, for keeping the passenger compartment in a properly air-conditioned state.
Japanese Patent Application Public Disclosure No. Hei 1-190520, for example, discloses an air conditioning system for vehicles, in which an air-distribution door for regulating the air-distribution ratio is controlled in response to an output signal generated by a solar radiation detector and at least a certain lower limit amount of air is supplied to each side of the passenger compartment by the air-distribution control operation irrespective of the direction of the sun relative to the traveling direction of the vehicle.
In this conventional system in which the air-distribution ratio is controlled in response to the direction of the sun, the air-distribution door is controlled so as to supply a greater amount of air to the side of the passenger compartment receiving more solar radiation than to the other side. Although this arrangement can eliminate imbalances in heat quantity within the passenger compartment, it does not give adequate consideration to controlling such factors as the flow pattern and flow volume of the air blowing on the occupants so as to increase their comfort.